PROJECT SUMMARY Despite increased access to early detection and the availability of more effective therapeutic strategies, African American women continue to experience excess rates of morbidity and mortality from breast cancer. One hypothesis about breast cancer disparities is that social conditions and physiological responses to social stressors influence biological processes that are important to the initiation and progression of disease. This hypothesis is based on data from animal studies which have shown that rats that are exposed to social stressors are likely to develop mammary tumors that are histologically and etiologically similar to those that develop among African American women. The HPA axis plays a central role in regulating the physiological stress response; dysregulation of the HPA has been suggested as a mechanism through which social and biological factors contribute to racial disparities in breast cancer outcomes. Many African Americans experience stressful life events and circumstances, including economic, discriminatory, and other stressors. These social factors may contribute to an increased risk of advanced stage disease, but not all African American women who are exposed to adverse social factors develop advanced stage disease and those who have a limited number of stressors can develop advanced stage breast cancer. This may be because stress reactivity is highly individualized. But, stress reactivity and the association between these responses and cognitive mechanisms and adherence to recommendations for cancer control behaviors and treatment compliance have not been examined among women at increased risk for disparities. Therefore, in response to RFA-RM-17-028, Science of Behavior Change: Use-inspired Research to Optimize Adherence, Behavior Change Interventions, and Outcomes (R21), we propose to examine stress reactivity among African American breast cancer survivors. The specific aims of this exploratory study are to: (1) characterize the nature and distribution of stress reactivity among African American breast cancer survivors based on socioeconomic, clinical, and social stressors; (2) examine the relationship between stress reactivity and cognitive mechanisms (e.g., self-efficacy, temporal discounting, and executive control); and (3) determine the extent to which stress reactivity is associated with adherence to recommendations for cancer control behaviors and treatment compliance. The proposed exploratory study will examine key mechanisms that are central to the Science of Behavior Change Network in a novel population and will identify intervention targets that can be used to improve behavioral compliance in a population that is at risk for poor outcomes after being diagnosed with breast cancer.